1. Field of the Invention
The present invention relates to a method of fabricating a cliché capable of preventing a printing roller from touching a bottom surface of the cliché.
2. Discussion of the Related Art
Recently, a variety of Flat Panel Displays (FPDs) are receiving attention as devices with reduced weight and volume to overcome disadvantages of a Cathode Ray Tube (CRT). FPDs include, for example, Liquid Crystal Displays (LCDs), Field Emission Displays (FEDs), Plasma Display Panels (PDPs), Electro-Luminescent (EL) displays, etc.
Such an FPD consists of a plurality of thin films formed by a mask process, which includes a deposition (coating) process, an exposure process, a developing process, an etching process, and the like. However, the mask process has a problem in that fabricating processes are complicated, thereby increasing fabrication costs. Hence, studies into forming the thin film through a printing process using a printing roller are recently underway.
The printing process refers to a process of forming a desired thin film in such a manner that the printing roller is coated, at a blanket thereof, with printing liquid, is formed with a printing pattern using a cliché having a groove pattern and a protrusion pattern, and then transfers the printing pattern onto a substrate.
Here, when the groove pattern 12 of the cliché 10 has a lower depth than that to which the printing roller 20 is pressed, as shown in FIG. 1, the printing roller 20 touches a bottom surface of the groove pattern 12 of the cliché 10 (see “A”). Consequently, the printing liquid 22 coated on the printing roller 20 is transferred to the bottom surface of the groove pattern 12 of the cliché 10, thereby being lost. When such lost printing liquid is transferred onto the substrate, a non-thin film region of a pinhole form is generated at a thin film layer. When the thin film layer is, particularly, used as a black matrix or a color filter to realize colors, there is a problem of causing a poor pattern such as decolorization in which colors are invisible at the non-thin film region of the thin film layer. In addition, when the thin film layers are formed on the respective substrates of a plurality of panels using the cliché 10 with the bottom surface touching the printing roller 20, there is a problem in that the same defects are respectively generated at the same positions of all the substrates, thereby causing deterioration of yield.